The Tcpdump Group git mirrors - tcpdump/blob - print-pppoe.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #ifndef lint
  23 static const char rcsid[] =
  24 "@(#) $Header: /tcpdump/master/tcpdump/print-pppoe.c,v 1.14 2001-06-20 07:40:44 guy Exp $ (LBL)";
  25 #endif
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/socket.h>
  34
  35 #include <netinet/in.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39
  40 #include "interface.h"
  41 #include "addrtoname.h"
  42 #include "ppp.h"
  43 #include "ethertype.h"
  44 #include "ether.h"
  45 #include "extract.h"                    /* must come after interface.h */
  46
  47 /* Codes */
  48 enum {
  49         PPPOE_PADI = 0x09,
  50         PPPOE_PADO = 0x07,
  51         PPPOE_PADR = 0x19,
  52         PPPOE_PADS = 0x65,
  53         PPPOE_PADT = 0xa7
  54 };
  55
  56 static struct tok pppoecode2str[] = {
  57         { PPPOE_PADI, "PADI" },
  58         { PPPOE_PADO, "PADO" },
  59         { PPPOE_PADR, "PADR" },
  60         { PPPOE_PADS, "PADS" },
  61         { PPPOE_PADT, "PADT" },
  62         { 0, "" }, /* PPP Data */
  63         { 0, NULL }
  64 };
  65
  66 /* Tags */
  67 enum {
  68         PPPOE_EOL = 0,
  69         PPPOE_SERVICE_NAME = 0x0101,
  70         PPPOE_AC_NAME = 0x0102,
  71         PPPOE_HOST_UNIQ = 0x0103,
  72         PPPOE_AC_COOKIE = 0x0104,
  73         PPPOE_VENDOR = 0x0105,
  74         PPPOE_RELAY_SID = 0x0110,
  75         PPPOE_SERVICE_NAME_ERROR = 0x0201,
  76         PPPOE_AC_SYSTEM_ERROR = 0x0202,
  77         PPPOE_GENERIC_ERROR = 0x0203
  78 };
  79
  80 static struct tok pppoetag2str[] = {
  81         { PPPOE_EOL, "EOL" },
  82         { PPPOE_SERVICE_NAME, "Service-Name" },
  83         { PPPOE_AC_NAME, "AC-Name" },
  84         { PPPOE_HOST_UNIQ, "Host-Uniq" },
  85         { PPPOE_AC_COOKIE, "AC-Cookie" },
  86         { PPPOE_VENDOR, "Vendor-Specific" },
  87         { PPPOE_RELAY_SID, "Relay-Session-ID" },
  88         { PPPOE_SERVICE_NAME_ERROR, "Service-Name-Error" },
  89         { PPPOE_AC_SYSTEM_ERROR, "AC-System-Error" },
  90         { PPPOE_GENERIC_ERROR, "Generic-Error" },
  91         { 0, NULL }
  92 };
  93
  94 #define PPPOE_HDRLEN 6
  95
  96 void
  97 pppoe_if_print(u_char *user, const struct pcap_pkthdr *h,
  98              register const u_char *p)
  99 {
 100         register u_int length = h->len;
 101         register u_int caplen = h->caplen;
 102
 103         ts_print(&h->ts);
 104
 105         /*
 106          * Some printers want to get back at the link level addresses,
 107          * and/or check that they're not walking off the end of the packet.
 108          * Rather than pass them all the way down, we set these globals.
 109          */
 110         packetp = p;
 111         snapend = p + caplen;
 112
 113         pppoe_print(p, length);
 114 }
 115
 116 void
 117 pppoe_print(register const u_char *bp, u_int length)
 118 {
 119         u_short pppoe_ver, pppoe_type, pppoe_code, pppoe_sessionid, pppoe_length;
 120         const u_char *pppoe_packet, *pppoe_payload;
 121
 122         pppoe_packet = bp;
 123         if (pppoe_packet > snapend) {
 124                 printf("[|pppoe]");
 125                 return;
 126         }
 127
 128         pppoe_ver  = (pppoe_packet[0] & 0xF0) >> 4;
 129         pppoe_type  = (pppoe_packet[0] & 0x0F);
 130         pppoe_code = pppoe_packet[1];
 131         pppoe_sessionid = EXTRACT_16BITS(pppoe_packet + 2);
 132         pppoe_length    = EXTRACT_16BITS(pppoe_packet + 4);
 133         pppoe_payload = pppoe_packet + PPPOE_HDRLEN;
 134
 135         if (snapend < pppoe_payload) {
 136                 printf(" truncated PPPoE");
 137                 return;
 138         }
 139
 140         if (pppoe_ver != 1) {
 141                 printf(" [ver %d]",pppoe_ver);
 142         }
 143         if (pppoe_type != 1) {
 144                 printf(" [type %d]",pppoe_type);
 145         }
 146
 147         printf("PPPoE %s", tok2str(pppoecode2str, "PAD-%x", pppoe_code));
 148         if (pppoe_code == PPPOE_PADI && pppoe_length > 1484 - PPPOE_HDRLEN) {
 149                 printf(" [len %d!]",pppoe_length);
 150         }
 151         if (pppoe_sessionid) {
 152                 printf(" [ses 0x%x]", pppoe_sessionid);
 153         }
 154
 155         if (pppoe_payload + pppoe_length < snapend) {
 156 #if 0
 157                 const u_char *x = pppoe_payload + pppoe_length;
 158                 printf(" [length %d (%d extra bytes)]",
 159                     pppoe_length, snapend - pppoe_payload - pppoe_length);
 160                 default_print(x, snapend - x);
 161 #endif
 162                 snapend = pppoe_payload+pppoe_length;
 163         }
 164
 165         if (pppoe_code) {
 166                 /* PPP session packets don't contain tags */
 167                 u_short tag_type = 0xffff, tag_len;
 168                 const u_char *p = pppoe_payload;
 169
 170                 /*
 171                  * loop invariant:
 172                  * p points to next tag,
 173                  * tag_type is previous tag or 0xffff for first iteration
 174                  */
 175                 while (tag_type && p + 4 < pppoe_payload + length &&
 176                     p + 4 < snapend) {
 177                         tag_type = EXTRACT_16BITS(p);
 178                         tag_len = EXTRACT_16BITS(p + 2);
 179                         p += 4;
 180                         /* p points to tag_value */
 181
 182                         if (tag_len) {
 183                                 int isascii = 1;
 184                                 const u_char *v = p;
 185                                 u_short l;
 186
 187                                 for (v = p; v < p + tag_len; v++)
 188                                         if (*v >= 127 || *v < 32) {
 189                                                 isascii = 0;
 190                                                 break;
 191                                         }
 192
 193                                 /* TODO print UTF8 decoded text */
 194                                 if (isascii) {
 195                                         l = (tag_len < 80 ? tag_len : 80);
 196                                         printf(" [%s \"%*.*s\"]",
 197                                             tok2str(pppoetag2str, "TAG-0x%x", tag_type),
 198                                             l, l, p);
 199                                 } else
 200                                         printf(" [%s UTF8]",
 201                                             tok2str(pppoetag2str, "TAG-0x%x", tag_type));
 202                         } else
 203                                 printf(" [%s]", tok2str(pppoetag2str,
 204                                     "TAG-0x%x", tag_type));
 205
 206                         p += tag_len;
 207                         /* p points to next tag */
 208                 }
 209         } else {
 210                 printf(" ");
 211                 ppp_print(pppoe_payload, pppoe_length);
 212         }
 213         return;
 214 }